U.S. patent application number 16/824746 was filed with the patent office on 2020-07-23 for system and method for measuring depth of instrumentation.
The applicant listed for this patent is GLOBUS MEDICAL, INC.. Invention is credited to Neil Crawford, Chris Major.
Application Number | 20200229888 16/824746 |
Document ID | / |
Family ID | 58256900 |
Filed Date | 2020-07-23 |
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United States Patent
Application |
20200229888 |
Kind Code |
A1 |
Crawford; Neil ; et
al. |
July 23, 2020 |
SYSTEM AND METHOD FOR MEASURING DEPTH OF INSTRUMENTATION
Abstract
Devices, systems, and methods for measuring the distance and/or
depth to a target bone for surgery using a robotic surgical system.
The surgical robot system may be configured to depict the distance
from a guide tube of the robot to a target bone of a patient as a
vector. The vector may represent a view of the guide tube when the
guide tube's central axis is coincident with a line of intersection
of two viewplanes of a 2D image of the target bone, for example,
one viewplane being sagittal and one viewplane being axial.
Inventors: |
Crawford; Neil; (Chandler,
AZ) ; Major; Chris; (Reisterstown, MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GLOBUS MEDICAL, INC. |
Audubon |
PA |
US |
|
|
Family ID: |
58256900 |
Appl. No.: |
16/824746 |
Filed: |
March 20, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15343255 |
Nov 4, 2016 |
10624710 |
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16824746 |
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15157444 |
May 18, 2016 |
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15343255 |
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15095883 |
Apr 11, 2016 |
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15157444 |
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14062707 |
Oct 24, 2013 |
10357184 |
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15095883 |
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13924505 |
Jun 21, 2013 |
9782229 |
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14062707 |
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61662702 |
Jun 21, 2012 |
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61800527 |
Mar 15, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2090/0811 20160201;
A61B 2034/2051 20160201; A61B 2034/2055 20160201; A61B 2034/2059
20160201; A61B 17/3423 20130101; A61B 90/11 20160201; A61B 2090/062
20160201; A61B 90/06 20160201; A61B 2034/2072 20160201; A61B 5/064
20130101; A61B 34/20 20160201; A61B 2090/3945 20160201; A61B
2034/2057 20160201; A61B 2090/034 20160201; A61B 17/17 20130101;
A61B 34/30 20160201; A61B 2090/373 20160201; A61B 2090/3762
20160201; A61B 34/25 20160201; A61B 90/96 20160201; A61B 2090/061
20160201; A61B 90/98 20160201; A61B 2017/00876 20130101; A61B
2090/376 20160201; A61B 2090/3937 20160201 |
International
Class: |
A61B 90/00 20060101
A61B090/00; A61B 34/30 20060101 A61B034/30; A61B 17/34 20060101
A61B017/34; A61B 34/20 20060101 A61B034/20; A61B 90/98 20060101
A61B090/98; A61B 5/06 20060101 A61B005/06; A61B 90/96 20060101
A61B090/96 |
Claims
1. A surgical system configured to indirectly determine a depth of
a surgical tool relative to a target bone of a patient during a
surgical operation based on a tracked tool guide to which the
surgical tool is slidably coupled without tracking the surgical
tool itself, the system comprising: a tracked tool guide having a
tracking marker; a surgical tool having depth markings and
configured to slidably couple to the tool guide, the depth markings
allowing a user to determine the depth of the surgical tool
relative to the tool guide to which the surgical tool is slidably
coupled; a tracking subsystem having a position sensor that
recognizes the tracking marker in a navigational space; a platform
interface module configured to receive a signal from the tracking
subsystem indicative of a position of the tool guide based on the
recognized tracking marker; a computer subsystem, including a
computer and a display, configured to receive a first viewplane
slice of the target bone from a 3D image volume of the patient;
wherein the computer is configured to receive the position of the
tool guide from the platform interface module, and display in the
display the received first viewplane slice and a vector overlaid on
the first viewplane slice which is indicative of the depth to
contact the target bone of the patient relative to the tool guide,
thereby allowing the user to compare a desired depth based on the
displayed vector and the actual depth of the surgical tool relative
to the tracked tool.
2. The system of claim 1, wherein the computer displays in the
display a virtual representation of the tool guide and the vector
including a plurality of evenly spaced markings that indicate the
depth from the tool guide towards the target bone.
3. The system of claim 1, wherein the computer is configured to
reduce the increments of the markings as the user zooms in on the
displayed first viewplane slice.
4. The system of claim 1, wherein the tool guide includes a tube
which is part of an end effector of a robot and the surgical tool
is configured to be inserted into the tube.
5. The system of claim 2, wherein the surgical tool contains
graduated markings indicating the actual depth of the surgical tool
past a selected point of the tool guide.
6. The system of claim 1, wherein: the computer is configured to
receive a second viewplane slice of the target bone from the 3D
image volume of the patient, the second viewplane slice
intersecting with the first viewplane slice at an angle in the 3D
image volume; wherein the computer is configured to display in the
display the received second viewplane slice and a vector overlaid
on the second viewplane slice which is indicative of the depth to
contact the target bone of the patient relative to the tool
guide.
7. The system of claim 1, wherein the surgical tool includes a
dilator having the graduated markings and configured to be inserted
into the tool guide.
8. A method for indirectly determining a depth of a surgical tool
relative to a target bone of a patient during a surgical operation
based on a tracked tool guide to which the surgical tool is
slidably coupled without tracking the surgical tool itself, the
method comprising: receiving, by a computer subsystem having a
computer and a display, a first viewplane slice of the target bone
from a 3D image volume of the patient; slidably coupling a surgical
tool to the tracked tool guide having a tracking marker, the
surgical tool having depth markings allowing a user to determine
the depth of the surgical tool relative to the coupled tool guide;
receiving a signal from a position sensor indicative of a position
of the tool guide based on the tracking marker; determining, by the
computer subsystem, a position of the tool guide in navigational
space based on the received signal; displaying in the display the
first viewplane slice and a vector overlaid on the first viewplane
slice which is indicative of the depth to contact the target bone
of the patient relative to the tool guide, thereby allowing the
user to compare a desired depth of the surgical tool based on the
displayed vector and the actual depth of the surgical tool relative
to the tool guide based on the depth markings.
9. The method of claim 8, wherein the step of displaying includes
displaying a virtual representation of the tool guide and the
vector including a plurality of evenly spaced markings that
indicate the depth from the tool guide towards the target bone.
10. The method of claim 8, wherein the step of displaying includes
changing the increments of markings in the vector automatically
based upon a level of zoom.
11. The method of claim 8, wherein: the tool guide includes a guide
tube which is part of an end effector of a robot arm; and the step
of slidably coupling includes inserting the surgical tool into the
guide tube.
12. The method of claim 11, wherein the surgical tool contains
graduated markings indicating the actual depth of the surgical tool
past a selected point of the guide tube.
13. The method of claim 8, wherein: the step of receiving includes
receiving a second viewplane slice of the target bone from the 3D
image volume of the patient, the second viewplane slice
intersecting with the first viewplane slice at an angle in the 3D
image volume; the step of displaying includes displaying the
received second viewplane slice and a vector overlaid on the second
viewplane slice which is indicative of the depth to contact the
target bone of the patient relative to the tool guide.
14. The method of claim 8, wherein: the tool guide includes a guide
tube which is part of an end effector of a robot arm; and the step
of slidably coupling includes inserting a dilator with depth
markings into the guide tube.
15. The method of claim 11, wherein the tool guide is attached to
an end effector and the tool guide is tracked separately from the
end effector.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/343,255, filed Nov. 4, 2016, which is a
continuation-in-part of U.S. patent application Ser. No. 15/157,444
filed May 18, 2016, which is a continuation-in-part application of
U.S. patent application Ser. No. 15/095,883 filed on Apr. 11, 2016
(published as U.S. Patent Publication No. 2016/0220320 A1), which
is a continuation-in-part application of U.S. patent application
Ser. No. 14/062,707 filed on Oct. 24, 2013 (published as U.S.
Patent Publication No. 2014/0275955 A1), which is a
continuation-in-part application of U.S. patent application Ser.
No. 13/924,505 filed on Jun. 21, 2013 (published as U.S. Patent
Publication No. 2013/0345718 A1, with corrected publication as U.S.
Patent Publication No. 2016/0242849 A9), which is a nonprovisional
patent application that claims priority to U.S. provisional patent
application No. 61/662,702 filed on Jun. 21, 2012, and claims
priority to U.S. provisional patent application No. 61/800,527
filed on Mar. 15, 2013, the entire contents of all of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present disclosure relates to position recognition
systems, and in particular, position recognition systems that allow
measurement of instrumentation and tools in a patient using
robot-assisted surgical techniques.
BACKGROUND OF THE INVENTION
[0003] Various medical procedures require the accurate localization
of a three-dimensional position of a surgical instrument within the
body in order to effect optimized treatment. For example, some
surgical procedures to fuse vertebrae require that a surgeon drill
multiple holes into the bone structure at specific locations. To
achieve high levels of mechanical integrity in the fusing system,
and to balance the forces created in the bone structure, it is
necessary that the holes are drilled at the correct location.
Vertebrae, like most bone structures, have complex shapes including
non-planar curved surfaces making accurate and perpendicular
drilling difficult. Conventionally, a surgeon manually holds and
positions a drill guide tube by using a guidance system to overlay
the drill tube's position onto a three dimensional image of the
bone structure. This manual process is both tedious and time
consuming. The success of the surgery is largely dependent upon the
dexterity of the surgeon who performs it.
[0004] When a surgeon performs minimally invasive surgery and
prepares to place a screw into bone, it is often desirable to
insert a dilator tube from the surface of the skin through muscle
and connective tissue down to a position where the distal end of
the dilator tube is adjacent to bone. The dilator tube serves as a
corridor through which drilling and other surgical steps can occur.
Currently, the most frequently used method for gauging whether the
dilator is sufficiently far enough inserted is to record x-ray
images, which is effective but exposes the patient and surgical
staff to x-rays and can be time consuming. If image guidance were
to be used instead of x-rays, it would spare the patient and staff
some exposure to x-rays. However, a tracking array mounted on a
dilator tube has the drawbacks that it is unwieldy and obtrusive to
the surgeon in an area where a great deal of surgical activity is
occurring.
[0005] Thus, there is a need to be able to measure the depth of
surgical instrumentation in a manner that limits the exposure of
the patient and medical staff to unnecessary radiation from imaging
systems without obstructing and impeding a medical staff's ability
to perform the surgical operation on the patient. The present
disclosure overcomes the disadvantages of current traditional
surgical techniques and robot-assisted surgical techniques. For
example, using known positions of components of a robot surgical
system allows a surgeon to position a long shaft such as a dilator
tube within a secondary tracked tube, such as the robot's end
effector guide tube or a free tracked external guide tube, to a
depth such that the dilator tube contacts the target bony
structure. This positioning would allow tracking the dilator tube
indirectly without tracking the dilator itself and without the use
of x-ray images as it is further inserted into a patient.
SUMMARY OF THE INVENTION
[0006] To meet this and other needs, devices, systems, and methods
for determining the distance or depth for a surgical instrument to
contact a target bone of a patient during robot assisted surgery is
provided.
[0007] According to one exemplary embodiment, a surgical robot
system may be configured to determine a distance for a surgical
instrument to contact a target bone of a patient during a surgical
operation. The system may include a guide tube comprising a
tracking marker and wherein the guide tube may be configured to
receive the surgical instrument, a tracking subsystem having a
position sensor that recognizes the tracking marker in a
navigational space, a platform interface module that may be
configured to receive a signal from the tracking subsystem
indicative of a position of the guide tube based on the tracking
marker, and a computer subsystem, including a computer and a
display, that may be configured to receive a first viewplane scan
of the target bone and a second viewplane scan of the target bone.
The first viewplane and the second viewplane may form an
intersection of views of the target bone. The computer subsystem
may also be configured to receive the position of the guide tube
from the platform interface module and may depict a vector
indicative of the distance to contact the target bone of the
patient, relative to a distal portion of the guide tube, on at
least one of the first viewplane scan and the second viewplane
scan, and wherein the vector may represent a central axis of the
guide tube being coincident to the intersection.
[0008] According to another embodiment, a method for determining
the distance for a surgical instrument to contact a target bone of
a patient during a surgical operating using a robotic surgical
system may be provided. The method may include receiving, by a
computer subsystem having a computer and a display, a first
viewplane scan of the target bone and a second viewplane scan of
the target bone, wherein the first viewplane and the second
viewplane form an intersection of views of the target bone in an
image space. The method may also include receiving, by the computer
subsystem, a position of a guide tube in navigational space, and
determining, by the computer, a distance between a distal portion
of the guide tube to the target bone of the patient, wherein the
distance may be determined such that a central axis of the guide
tube is coincident to the intersection. The method may also include
depicting, via the display, a vector indicative of the distance to
contact the target bone of the patient on at least one of the first
viewplane scan and the second viewplane scan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention and the following detailed description of
certain embodiments thereof may be understood by reference to the
following figures:
[0010] FIG. 1 is an overhead view of a potential arrangement for
locations of the robotic system, patient, surgeon, and other
medical personnel during a surgical procedure;
[0011] FIG. 2 illustrates the robotic system including positioning
of the surgical robot and the camera relative to the patient
according to one embodiment;
[0012] FIG. 3 illustrates a surgical robotic system in accordance
with an exemplary embodiment;
[0013] FIG. 4 illustrates a portion of a surgical robot in
accordance with an exemplary embodiment;
[0014] FIG. 5 illustrates a block diagram of a surgical robot in
accordance with an exemplary embodiment;
[0015] FIG. 6 illustrates a surgical robot in accordance with an
exemplary embodiment;
[0016] FIGS. 7A-7C illustrate an end effector in accordance with an
exemplary embodiment;
[0017] FIG. 8 illustrates a surgical instrument and the end
effector, before and after, inserting the surgical instrument into
the guide tube of the end effector according to one embodiment;
[0018] FIGS. 9A-9C illustrate portions of an end effector and robot
arm in accordance with an exemplary embodiment;
[0019] FIG. 10 illustrates a dynamic reference array, an imaging
array, and other components in accordance with an exemplary
embodiment;
[0020] FIG. 11 illustrates a method of registration in accordance
with an exemplary embodiment;
[0021] FIG. 12A-12B illustrate embodiments of imaging devices
according to exemplary embodiments;
[0022] FIG. 13 illustrates an exemplary image of a viewplane x-ray
with associated depictions measuring depth to a target bone;
[0023] FIG. 14 illustrates an exemplary image of a viewplane of an
x-ray with associated depictions measuring depth to a target
bone;
[0024] FIG. 15 illustrates an exemplary image of a viewplane of an
x-ray with associated depictions measuring depth to a target
bone;
[0025] FIG. 16 illustrates an exemplary image of a viewplane of an
x-ray with associated depictions measuring depth to a target
bone;
[0026] FIG. 17 illustrates an exemplary image of a viewplane of an
x-ray with associated depictions measuring depth to a target
bone;
[0027] FIG. 18 illustrates an exemplary instrument with markings
consistent with the present disclosure;
[0028] FIG. 19 illustrates an exemplary instrument and guide tube
consistent with the present disclosure;
[0029] FIG. 20 illustrates an exemplary method consistent with the
present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0030] It is to be understood that the present disclosure is not
limited in its application to the details of construction and the
arrangement of components set forth in the description herein or
illustrated in the drawings. The teachings of the present
disclosure may be used and practiced in other embodiments and
practiced or carried out in various ways. Also, it is to be
understood that the phraseology and terminology used herein is for
the purpose of description and should not be regarded as limiting.
The use of "including," "comprising," or "having" and variations
thereof herein is meant to encompass the items listed thereafter
and equivalents thereof as well as additional items. Unless
specified or limited otherwise, the terms "mounted," "connected,"
"supported," and "coupled" and variations thereof are used broadly
and encompass both direct and indirect mountings, connections,
supports, and couplings. Further, "connected" and "coupled" are not
restricted to physical or mechanical connections or couplings.
[0031] The following discussion is presented to enable a person
skilled in the art to make and use embodiments of the present
disclosure. Various modifications to the illustrated embodiments
will be readily apparent to those skilled in the art, and the
principles herein can be applied to other embodiments and
applications without departing from embodiments of the present
disclosure. Thus, the embodiments are not intended to be limited to
embodiments shown, but are to be accorded the widest scope
consistent with the principles and features disclosed herein. The
following detailed description is to be read with reference to the
figures, in which like elements in different figures have like
reference numerals. The figures, which are not necessarily to
scale, depict selected embodiments and are not intended to limit
the scope of the embodiments. Skilled artisans will recognize the
examples provided herein have many useful alternatives and fall
within the scope of the embodiments.
[0032] Turning now to the drawing, FIGS. 1 and 2 illustrate a
surgical robot system 100 in accordance with an exemplary
embodiment. Surgical robot system 100 may include, for example, a
surgical robot 102, one or more robot arms 104, a base 106, a
display 110, an end effector 112, for example, including a guide
tube 114, and one or more tracking markers 118. The surgical robot
system 100 may include a patient tracking device 116 also including
one or more tracking markers 118, which is adapted to be secured
directly to the patient 210 (e.g., to the bone of the patient 210).
The surgical robot system 100 may also utilize a camera 200, for
example, positioned on a camera stand 202. The camera stand 202 can
have any suitable configuration to move, orient, and support the
camera 200 in a desired position. The camera 200 may include any
suitable camera or cameras, such as one or more infrared cameras
(e.g., bifocal or stereophotogrammetric cameras), able to identify,
for example, active and passive tracking markers 118 in a given
measurement volume viewable from the perspective of the camera 200.
The camera 200 may scan the given measurement volume and detect the
light that comes from the markers 118 in order to identify and
determine the position of the markers 118 in three dimensions. For
example, active markers 118 may include infrared-emitting markers
that are activated by an electrical signal (e.g., infrared light
emitting diodes (LEDs)), and passive markers 118 may include
retro-reflective markers that reflect infrared light (e.g., they
reflect incoming IR radiation into the direction of the incoming
light), for example, emitted by illuminators on the camera 200 or
other suitable device.
[0033] FIGS. 1 and 2 illustrate a potential configuration for the
placement of the surgical robot system 100 in an operating room
environment. For example, the robot 102 may be positioned near or
next to patient 210. Although depicted near the head of the patient
210, it will be appreciated that the robot 102 can be positioned at
any suitable location near the patient 210 depending on the area of
the patient 210 undergoing the operation. The camera 200 may be
separated from the robot system 100 and positioned at the foot of
patient 210. This location allows the camera 200 to have a direct
visual line of sight to the surgical field 208. Again, it is
contemplated that the camera 200 may be located at any suitable
position having line of sight to the surgical field 208. In the
configuration shown, the surgeon 120 may be positioned across from
the robot 102, but is still able to manipulate the end effector 112
and the display 110. A surgical assistant 126 may be positioned
across from the surgeon 120 again with access to both the end
effector 112 and the display 110. If desired, the locations of the
surgeon 120 and the assistant 126 may be reversed. The traditional
areas for the anesthesiologist 122 and the nurse or scrub tech 124
remain unimpeded by the locations of the robot 102 and camera
200.
[0034] With respect to the other components of the robot 102, the
display 110 can be attached to the surgical robot 102 and in other
exemplary embodiments, display 110 can be detached from surgical
robot 102, either within a surgical room with the surgical robot
102, or in a remote location. End effector 112 may be coupled to
the robot arm 104 and controlled by at least one motor. In
exemplary embodiments, end effector 112 can comprise a guide tube
114, which is able to receive and orient a surgical instrument 608
(described further herein) used to perform surgery on the patient
210. As used herein, the term "end effector" is used
interchangeably with the terms "end-effectuator" and "effectuator
element." Although generally shown with a guide tube 114, it will
be appreciated that the end effector 112 may be replaced with any
suitable instrumentation suitable for use in surgery. In some
embodiments, end effector 112 can comprise any known structure for
effecting the movement of the surgical instrument 608 in a desired
manner.
[0035] The surgical robot 102 is able to control the translation
and orientation of the end effector 112. The robot 102 is able to
move end effector 112 along x-, y-, and z-axes, for example. The
end effector 112 can be configured for selective rotation about one
or more of the x-, y-, and z-axis, and a Z Frame axis (such that
one or more of the Euler Angles (e.g., roll, pitch, and/or yaw)
associated with end effector 112 can be selectively controlled). In
some exemplary embodiments, selective control of the translation
and orientation of end effector 112 can permit performance of
medical procedures with significantly improved accuracy compared to
conventional robots that utilize, for example, a six degree of
freedom robot arm comprising only rotational axes. For example, the
surgical robot system 100 may be used to operate on patient 210,
and robot arm 104 can be positioned above the body of patient 210,
with end effector 112 selectively angled relative to the z-axis
toward the body of patient 210.
[0036] In some exemplary embodiments, the position of the surgical
instrument 608 can be dynamically updated so that surgical robot
102 can be aware of the location of the surgical instrument 608 at
all times during the procedure. Consequently, in some exemplary
embodiments, surgical robot 102 can move the surgical instrument
608 to the desired position quickly without any further assistance
from a physician (unless the physician so desires). In some further
embodiments, surgical robot 102 can be configured to correct the
path of the surgical instrument 608 if the surgical instrument 608
strays from the selected, preplanned trajectory. In some exemplary
embodiments, surgical robot 102 can be configured to permit
stoppage, modification, and/or manual control of the movement of
end effector 112 and/or the surgical instrument 608. Thus, in use,
in exemplary embodiments, a physician or other user can operate the
system 100, and has the option to stop, modify, or manually control
the autonomous movement of end effector 112 and/or the surgical
instrument 608. Further details of surgical robot system 100
including the control and movement of a surgical instrument 608 by
surgical robot 102 can be found in co-pending U.S. patent
application Ser. No. 13/924,505, which is incorporated herein by
reference in its entirety.
[0037] The robotic surgical system 100 can comprise one or more
tracking markers 118 configured to track the movement of robot arm
104, end effector 112, patient 210, and/or the surgical instrument
608 in three dimensions. In exemplary embodiments, a plurality of
tracking markers 118 can be mounted (or otherwise secured) thereon
to an outer surface of the robot 102, such as, for example and
without limitation, on base 106 of robot 102, on robot arm 104, or
on the end effector 112. In exemplary embodiments, at least one
tracking marker 118 of the plurality of tracking markers 118 can be
mounted or otherwise secured to the end effector 112. One or more
tracking markers 118 can further be mounted (or otherwise secured)
to the patient 210. In exemplary embodiments, the plurality of
tracking markers 118 can be positioned on the patient 210 spaced
apart from the surgical field 208 to reduce the likelihood of being
obscured by the surgeon, surgical tools, or other parts of the
robot 102. Further, one or more tracking markers 118 can be further
mounted (or otherwise secured) to the surgical tools 608 (e.g., a
screw driver, dilator, implant inserter, or the like). Thus, the
tracking markers 118 enable each of the marked objects (e.g., the
end effector 112, the patient 210, and the surgical tools 608) to
be tracked by the robot 102. In exemplary embodiments, system 100
can use tracking information collected from each of the marked
objects to calculate the orientation and location, for example, of
the end effector 112, the surgical instrument 608 (e.g., positioned
in the tube 114 of the end effector 112), and the relative position
of the patient 210.
[0038] In exemplary embodiments, one or more of markers 118 may be
optical markers. In some embodiments, the positioning of one or
more tracking markers 118 on end effector 112 can maximize the
accuracy of the positional measurements by serving to check or
verify the position of end effector 112. Further details of
surgical robot system 100 including the control, movement and
tracking of surgical robot 102 and of a surgical instrument 608 can
be found in co-pending U.S. patent application Ser. No. 13/924,505,
which is incorporated herein by reference in its entirety.
[0039] Exemplary embodiments include one or more markers 118
coupled to the surgical instrument 608. In exemplary embodiments,
these markers 118, for example, coupled to the patient 210 and
surgical instruments 608, as well as markers 118 coupled to the end
effector 112 of the robot 102 can comprise conventional infrared
light-emitting diodes (LEDs) or an Optotrak.RTM. diode capable of
being tracked using a commercially available infrared optical
tracking system such as Optotrak.RTM.. Optotrak.RTM. is a
registered trademark of Northern Digital Inc., Waterloo, Ontario,
Canada. In other embodiments, markers 118 can comprise conventional
reflective spheres capable of being tracked using a commercially
available optical tracking system such as Polaris Spectra. Polaris
Spectra is also a registered trademark of Northern Digital, Inc. In
an exemplary embodiment, the markers 118 coupled to the end
effector 112 are active markers which comprise infrared
light-emitting diodes which may be turned on and off, and the
markers 118 coupled to the patient 210 and the surgical instruments
608 comprise passive reflective spheres.
[0040] In exemplary embodiments, light emitted from and/or
reflected by markers 118 can be detected by camera 200 and can be
used to monitor the location and movement of the marked objects. In
alternative embodiments, markers 118 can comprise a radio-frequency
and/or electromagnetic reflector or transceiver and the camera 200
can include or be replaced by a radio-frequency and/or
electromagnetic transceiver.
[0041] Similar to surgical robot system 100, FIG. 3 illustrates a
surgical robot system 300 and camera stand 302, in a docked
configuration, consistent with an exemplary embodiment of the
present disclosure. Surgical robot system 300 may comprise a robot
301 including a display 304, upper arm 306, lower arm 308, end
effector 310, vertical column 312, casters 314, cabinet 316, tablet
drawer 318, connector panel 320, control panel 322, and ring of
information 324. Camera stand 302 may comprise camera 326. These
components are described in greater with respect to FIG. 5. FIG. 3
illustrates the surgical robot system 300 in a docked configuration
where the camera stand 302 is nested with the robot 301, for
example, when not in use. It will be appreciated by those skilled
in the art that the camera 326 and robot 301 may be separated from
one another and positioned at any appropriate location during the
surgical procedure, for example, as shown in FIGS. 1 and 2. FIG. 4
illustrates a base 400 consistent with an exemplary embodiment of
the present disclosure. Base 400 may be a portion of surgical robot
system 300 and comprise cabinet 316. Cabinet 316 may house certain
components of surgical robot system 300 including but not limited
to a battery 402, a power distribution module 404, a platform
interface board module 406, a computer 408, a handle 412, and a
tablet drawer 414. The connections and relationship between these
components is described in greater detail with respect to FIG.
5.
[0042] FIG. 5 illustrates a block diagram of certain components of
an exemplary embodiment of surgical robot system 300. Surgical
robot system 300 may comprise platform subsystem 502, computer
subsystem 504, motion control subsystem 506, and tracking subsystem
532. Platform subsystem 502 may further comprise battery 402, power
distribution module 404, platform interface board module 406, and
tablet charging station 534. Computer subsystem 504 may further
comprise computer 408, display 304, and speaker 536. Motion control
subsystem 506 may further comprise driver circuit 508, motors 510,
512, 514, 516, 518, stabilizers 520, 522, 524, 526, end effector
310, and controller 538. Tracking subsystem 532 may further
comprise position sensor 540 and camera converter 542. System 300
may also comprise a foot pedal 544 and tablet 546.
[0043] Input power is supplied to system 300 via a power source 548
which may be provided to power distribution module 404. Power
distribution module 404 receives input power and is configured to
generate different power supply voltages that are provided to other
modules, components, and subsystems of system 300. Power
distribution module 404 may be configured to provide different
voltage supplies to platform interface module 406, which may be
provided to other components such as computer 408, display 304,
speaker 536, driver 508 to, for example, power motors 512, 514,
516, 518 and end effector 310, motor 510, ring 324, camera
converter 542, and other components for system 300 for example,
fans for cooling the electrical components within cabinet 316.
[0044] Power distribution module 404 may also provide power to
other components such as tablet charging station 534 that may be
located within tablet drawer 318. Tablet charging station 534 may
be in wireless or wired communication with tablet 546 for charging
table 546. Tablet 546 may be used by a surgeon consistent with the
present disclosure and described herein. Power distribution module
404 may also be connected to battery 402, which serves as temporary
power source in the event that power distribution module 404 does
not receive power from input power 548. At other times, power
distribution module 404 may serve to charge battery 402 if
necessary.
[0045] Other components of platform subsystem 502 may also include
connector panel 320, control panel 322, and ring 324. Connector
panel 320 may serve to connect different devices and components to
system 300 and/or associated components and modules. Connector
panel 320 may contain one or more ports that receive lines or
connections from different components. For example, connector panel
320 may have a ground terminal port that may ground system 300 to
other equipment, a port to connect foot pedal 544 to system 300, a
port to connect to tracking subsystem 532, which may comprise
position sensor 540, camera converter 542, and cameras 326
associated with camera stand 302. Connector panel 320 may also
include other ports to allow USB, Ethernet, HDMI communications to
other components, such as computer 408.
[0046] Control panel 322 may provide various buttons or indicators
that control operation of system 300 and/or provide information
regarding system 300. For example, control panel 322 may include
buttons to power on or off system 300, lift or lower vertical
column 312, and lift or lower stabilizers 520-526 that may be
designed to engage casters 314 to lock system 300 from physically
moving. Other buttons may stop system 300 in the event of an
emergency, which may remove all motor power and apply mechanical
brakes to stop all motion from occurring. Control panel 322 may
also have indicators notifying the user of certain system
conditions such as a line power indicator or status of charge for
battery 402.
[0047] Ring 324 may be a visual indicator to notify the user of
system 300 of different modes that system 300 is operating under
and certain warnings to the user.
[0048] Computer subsystem 504 includes computer 408, display 304,
and speaker 536. Computer 504 includes an operating system and
software to operate system 300. Computer 504 may receive and
process information from other components (for example, tracking
subsystem 532, platform subsystem 502, and/or motion control
subsystem 506) in order to display information to the user.
Further, computer subsystem 504 may also include speaker 536 to
provide audio to the user.
[0049] Tracking subsystem 532 may include position sensor 504 and
converter 542. Tracking subsystem 532 may correspond to camera
stand 302 including camera 326 as described with respect to FIG. 3.
Position sensor 504 may be camera 326. Tracking subsystem may track
the location of certain markers that are located on the different
components of system 300 and/or instruments used by a user during a
surgical procedure. This tracking may be conducted in a manner
consistent with the present disclosure including the use of
infrared technology that tracks the location of active or passive
elements, such as LEDs or reflective markers, respectively. The
location, orientation, and position of structures having these
types of markers may be provided to computer 408 which may be shown
to a user on display 304. For example, a surgical instrument 608
having these types of markers and tracked in this manner (which may
be referred to as a navigational space) may be shown to a user in
relation to a three dimensional image of a patient's anatomical
structure. Motion control subsystem 506 may be configured to
physically move vertical column 312, upper arm 306, lower arm 308,
or rotate end effector 310. The physical movement may be conducted
through the use of one or more motors 510-518. For example, motor
510 may be configured to vertically lift or lower vertical column
312. Motor 512 may be configured to laterally move upper arm 308
around a point of engagement with vertical column 312 as shown in
FIG. 3. Motor 514 may be configured to laterally move lower arm 308
around a point of engagement with upper arm 308 as shown in FIG. 3.
Motors 516 and 518 may be configured to move end effector 310 in a
manner such that one may control the roll and one may control the
tilt, thereby providing multiple angles that end effector 310 may
be moved. These movements may be achieved by controller 538 which
may control these movements through load cells disposed on end
effector 310 and activated by a user engaging these load cells to
move system 300 in a desired manner.
[0050] Moreover, system 300 may provide for automatic movement of
vertical column 312, upper arm 306, and lower arm 308 through a
user indicating on display 304 (which may be a touchscreen input
device) the location of a surgical instrument or component on three
dimensional image of the patient's anatomy on display 304. The user
may initiate this automatic movement by stepping on foot pedal 544
or some other input means.
[0051] FIG. 6 illustrates a surgical robot system 600 consistent
with an exemplary embodiment. Surgical robot system 600 may
comprise end effector 602, robot arm 604, guide tube 606,
instrument 608, and robot base 610. Instrument tool 608 may be
attached to a tracking array 612 including one or more tracking
markers (such as markers 118) and have an associated trajectory
614. Trajectory 614 may represent a path of movement that
instrument tool 608 is configured to travel once it is positioned
through or secured in guide tube 606, for example, a path of
insertion of instrument tool 608 into a patient. In an exemplary
operation, robot base 610 may be configured to be in electronic
communication with robot arm 604 and end effector 602 so that
surgical robot system 600 may assist a user (for example, a
surgeon) in operating on the patient 210. Surgical robot system 600
may be consistent with previously described surgical robot system
100 and 300.
[0052] A tracking array 612 may be mounted on instrument 608 to
monitor the location and orientation of instrument tool 608. The
tracking array 612 may be attached to an instrument 608 and may
comprise tracking markers 804. As best seen in FIG. 8, tracking
markers 804 may be, for example, light emitting diodes and/or other
types of reflective markers (e.g., markers 118 as described
elsewhere herein). The tracking devices may be one or more line of
sight devices associated with the surgical robot system. As an
example, the tracking devices may be one or more cameras 200, 326
associated with the surgical robot system 100, 300 and may also
track tracking array 612 for a defined domain or relative
orientations of the instrument 608 in relation to the robot arm
604, the robot base 610, end effector 602, and/or the patient 210.
The tracking devices may be consistent with those structures
described in connection with camera stand 302 and tracking
subsystem 532.
[0053] FIGS. 7A, 7B, and 7C illustrate a top view, front view, and
side view, respectively, of end effector 602 consistent with an
exemplary embodiment. End effector 602 may comprise one or more
tracking markers 702. Tracking markers 702 may be light emitting
diodes or other types of active and passive markers, such as
tracking markers 118 that have been previously described. In an
exemplary embodiment, the tracking markers 702 are active
infrared-emitting markers that are activated by an electrical
signal (e.g., infrared light emitting diodes (LEDs)). Thus,
tracking markers 702 may be activated such that the infrared
markers 702 are visible to the camera 200, 326 or may be
deactivated such that the infrared markers 702 are not visible to
the camera 200, 326. Thus, when the markers 702 are active, the end
effector 602 may be controlled by the system 100, 300, 600, and
when the markers 702 are deactivated, the end effector 602 may be
locked in position and unable to be moved by the system 100, 300,
600.
[0054] Markers 702 may be disposed on or within end effector 602 in
a manner such that the markers 702 are visible by one or more
cameras 200, 326 or other tracking devices associated with the
surgical robot system 100, 300, 600. The camera 200, 326 or other
tracking devices may track end effector 602 as it moves to
different positions and viewing angles by following the movement of
tracking markers 702. The location of markers 702 and/or end
effector 602 may be shown on a display 110, 304 associated with the
surgical robot system 100, 300, 600, for example, display 110 as
shown in FIG. 2 and/or display 304 shown in FIG. 3. This display
110, 304 may allow a user to ensure that end effector 602 is in a
desirable position in relation to robot arm 604, robot base 610,
the patient 210, and/or the user.
[0055] For example, as shown in FIG. 7A, markers 702 may be placed
around the surface of end effector 602 so that a tracking device
placed away from the surgical field 208 and facing toward the robot
102, 301 and the camera 200, 326 is able to view at least 3 of the
markers 702 through a range of common orientations of the end
effector 602 relative to the tracking device 100, 300, 600. For
example, distribution of markers 702 in this way allows end
effector 602 to be monitored by the tracking devices when end
effector 602 is translated and rotated in the surgical field
208.
[0056] In addition, in exemplary embodiments, end effector 602 may
be equipped with infrared (IR) receivers that can detect when an
external camera 200, 326 is getting ready to read markers 702. Upon
this detection, end effector 602 may then illuminate markers 702.
The detection by the IR receivers that the external camera 200, 326
is ready to read markers 702 may signal the need to synchronize a
duty cycle of markers 702, which may be light emitting diodes, to
an external camera 200, 326. This may also allow for lower power
consumption by the robotic system as a whole, whereby markers 702
would only be illuminated at the appropriate time instead of being
illuminated continuously. Further, in exemplary embodiments,
markers 702 may be powered off to prevent interference with other
navigation tools, such as different types of surgical instruments
608.
[0057] FIG. 8 depicts one type of surgical instrument 608 including
a tracking array 612 and tracking markers 804. Tracking markers 804
may be of any type described herein including but not limited to
light emitting diodes or reflective spheres. Markers 804 are
monitored by tracking devices associated with the surgical robot
system 100, 300, 600 and may be one or more of the line of sight
cameras 200, 326. The cameras 200, 326 may track the location of
instrument 608 based on the position and orientation of tracking
array 612 and markers 804. A user, such as a surgeon 120, may
orient instrument 608 in a manner so that tracking array 612 and
markers 804 are sufficiently recognized by the tracking device or
camera 200, 326 to display instrument 608 and markers 804 on, for
example, display 110 of the exemplary surgical robot system.
[0058] The manner in which a surgeon 120 may place instrument 608
into guide tube 606 of the end effector 602 and adjust the
instrument 608 is evident in FIG. 8. The hollow tube or guide tube
114, 606 of the end effector 112, 310, 602 is sized and configured
to receive at least a portion of the surgical instrument 608. The
guide tube 114, 606 is configured to be oriented by the robot arm
104 such that insertion and trajectory for the surgical instrument
608 is able to reach a desired anatomical target within or upon the
body of the patient 210. The surgical instrument 608 may include at
least a portion of a generally cylindrical instrument. Although a
screw driver is exemplified as the surgical tool 608, it will be
appreciated that any suitable surgical tool 608 may be positioned
by the end effector 602. By way of example, the surgical instrument
608 may include one or more of a guide wire, cannula, a retractor,
a drill, a reamer, a screw driver, an insertion tool, a removal
tool, or the like. Although the hollow tube 114, 606 is generally
shown as having a cylindrical configuration, it will be appreciated
by those of skill in the art that the guide tube 114, 606 may have
any suitable shape, size and configuration desired to accommodate
the surgical instrument 608 and access the surgical site.
[0059] FIGS. 9A-9C illustrate end effector 602 and a portion of
robot arm 604 consistent with an exemplary embodiment. End effector
602 may further comprise body 1202 and clamp 1204. Clamp 1204 may
comprise handle 1206, balls 1208, spring 1210, and lip 1212. Robot
arm 604 may further comprise depressions 1214, mounting plate 1216,
lip 1218, and magnets 1220.
[0060] End effector 602 may mechanically interface and/or engage
with the surgical robot system and robot arm 604 through one or
more couplings. For example, end effector 602 may engage with robot
arm 604 through a locating coupling and/or a reinforcing coupling.
Through these couplings, end effector 602 may fasten with robot arm
604 outside a flexible and sterile barrier. In an exemplary
embodiment, the locating coupling may be a magnetically kinematic
mount and the reinforcing coupling may be a five bar over center
clamping linkage.
[0061] With respect to the locating coupling, robot arm 604 may
comprise mounting plate 1216, which may be non-magnetic material,
one or more depressions 1214, lip 1218, and magnets 1220. Magnet
1220 is mounted below each of depressions 1214. Portions of clamp
1204 may comprise magnetic material and be attracted by one or more
magnets 1220. Through the magnetic attraction of clamp 1204 and
robot arm 604, balls 1208 become seated into respective depressions
1214. For example, balls 1208 as shown in FIG. 9B would be seated
in depressions 1214 as shown in FIG. 9A. This seating may be
considered a magnetically-assisted kinematic coupling. Magnets 1220
may be configured to be strong enough to support the entire weight
of end effector 602 regardless of the orientation of end effector
602. The locating coupling may be any style of kinematic mount that
uniquely restrains six degrees of freedom.
[0062] With respect to the reinforcing coupling, portions of clamp
1204 may be configured to be a fixed ground link and as such clamp
1204 may serve as a five bar linkage. Closing clamp handle 1206 may
fasten end effector 602 to robot arm 604 as lip 1212 and lip 1218
engage clamp 1204 in a manner to secure end effector 602 and robot
arm 604. When clamp handle 1206 is closed, spring 1210 may be
stretched or stressed while clamp 1204 is in a locked position. The
locked position may be a position that provides for linkage past
center. Because of a closed position that is past center, the
linkage will not open absent a force applied to clamp handle 1206
to release clamp 1204. Thus, in a locked position end effector 602
may be robustly secured to robot arm 604.
[0063] Spring 1210 may be a curved beam in tension. Spring 1210 may
be comprised of a material that exhibits high stiffness and high
yield strain such as virgin PEEK (poly-ether-ether-ketone). The
linkage between end effector 602 and robot arm 604 may provide for
a sterile barrier between end effector 602 and robot arm 604
without impeding fastening of the two couplings.
[0064] The reinforcing coupling may be a linkage with multiple
spring members. The reinforcing coupling may latch with a cam or
friction based mechanism. The reinforcing coupling may also be a
sufficiently powerful electromagnet that will support fastening
end-effector 102 to robot arm 604. The reinforcing coupling may be
a multi-piece collar completely separate from either end effector
602 and/or robot arm 604 that slips over an interface between end
effector 602 and robot arm 604 and tightens with a screw mechanism,
an over center linkage, or a cam mechanism.
[0065] Referring to FIGS. 10 and 11, prior to or during a surgical
procedure, certain registration procedures may be conducted in
order to track objects and a target anatomical structure of the
patient 210 both in a navigation space and an image space. In order
to conduct such registration, a registration system 1400 may be
used as illustrated in FIG. 10.
[0066] In order to track the position of the patient 210, a patient
tracking device 116 may include a patient fixation instrument 1402
to be secured to a rigid anatomical structure of the patient 210
and a dynamic reference base (DRB) 1404 may be securely attached to
the patient fixation instrument 1402. For example, patient fixation
instrument 1402 may be inserted into opening 1406 of dynamic
reference base 1404. Dynamic reference base 1404 may contain
markers 1408 that are visible to tracking devices, such as tracking
subsystem 532. These markers 1408 may be optical markers or
reflective spheres, such as tracking markers 118, as previously
discussed herein.
[0067] Patient fixation instrument 1402 is attached to a rigid
anatomy of the patient 210 and may remain attached throughout the
surgical procedure. In an exemplary embodiment, patient fixation
instrument 1402 is attached to a rigid area of the patient 210, for
example, a bone that is located away from the targeted anatomical
structure subject to the surgical procedure. In order to track the
targeted anatomical structure, dynamic reference base 1404 is
associated with the targeted anatomical structure through the use
of a registration fixture that is temporarily placed on or near the
targeted anatomical structure in order to register the dynamic
reference base 1404 with the location of the targeted anatomical
structure.
[0068] A registration fixture 1410 is attached to patient fixation
instrument 1402 through the use of a pivot arm 1412. Pivot arm 1412
is attached to patient fixation instrument 1402 by inserting
patient fixation instrument 1402 through an opening 1414 of
registration fixture 1410. Pivot arm 1412 is attached to
registration fixture 1410 by, for example, inserting a knob 1416
through an opening 1418 of pivot arm 1412.
[0069] Using pivot arm 1412, registration fixture 1410 may be
placed over the targeted anatomical structure and its location may
be determined in an image space and navigation space using tracking
markers 1420 and/or fiducials 1422 on registration fixture 1410.
Registration fixture 1410 may contain a collection of markers 1420
that are visible in a navigational space (for example, markers 1420
may be detectable by tracking subsystem 532). Tracking markers 1420
may be optical markers visible in infrared light as previously
described herein. Registration fixture 1410 may also contain a
collection of fiducials 1422, for example, such as bearing balls,
that are visible in an imaging space (for example, a three
dimension CT image). As described in greater detail with respect to
FIG. 11, using registration fixture 1410, the targeted anatomical
structure may be associated with dynamic reference base 1404
thereby allowing depictions of objects in the navigational space to
be overlaid on images of the anatomical structure. Dynamic
reference base 1404, located at a position away from the targeted
anatomical structure, may become a reference point thereby allowing
removal of registration fixture 1410 and/or pivot arm 1412 from the
surgical area.
[0070] FIG. 11 provides an exemplary method 1500 for registration
consistent with the present disclosure. Method 1500 begins at step
1502 wherein a graphical representation (or image(s)) of the
targeted anatomical structure may be imported into system 100, 300
600, for example computer 408. The graphical representation may be
three dimensional CT or a fluoroscope scan of the targeted
anatomical structure of the patient 210 which includes registration
fixture 1410 and a detectable imaging pattern of fiducials
1420.
[0071] At step 1504, an imaging pattern of fiducials 1420 is
detected and registered in the imaging space and stored in computer
408. Optionally, at this time at step 1506, a graphical
representation of the registration fixture 1410 may be overlaid on
the images of the targeted anatomical structure.
[0072] At step 1508, a navigational pattern of registration fixture
1410 is detected and registered by recognizing markers 1420.
Markers 1420 may be optical markers that are recognized in the
navigation space through infrared light by tracking subsystem 532
via position sensor 540. Thus, the location, orientation, and other
information of the targeted anatomical structure is registered in
the navigation space. Therefore, registration fixture 1410 may be
recognized in both the image space through the use of fiducials
1422 and the navigation space through the use of markers 1420. At
step 1510, the registration of registration fixture 1410 in the
image space is transferred to the navigation space. This transferal
is done, for example, by using the relative position of the imaging
pattern of fiducials 1422 compared to the position of the
navigation pattern of markers 1420.
[0073] At step 1512, registration of the navigation space of
registration fixture 1410 (having been registered with the image
space) is further transferred to the navigation space of dynamic
registration array 1404 attached to patient fixture instrument
1402. Thus, registration fixture 1410 may be removed and dynamic
reference base 1404 may be used to track the targeted anatomical
structure in both the navigation and image space because the
navigation space is associated with the image space.
[0074] At steps 1514 and 1516, the navigation space may be overlaid
on the image space and objects with markers visible in the
navigation space (for example, surgical instruments 608 with
optical markers 804). The objects may be tracked through graphical
representations of the surgical instrument 608 on the images of the
targeted anatomical structure.
[0075] FIGS. 12A-12B illustrate imaging devices 1304 that may be
used in conjunction with robot systems 100, 300, 600 to acquire
pre-operative, intra-operative, post-operative, and/or real-time
image data of patient 210. Any appropriate subject matter may be
imaged for any appropriate procedure using the imaging system 1304.
The imaging system 1304 may be any imaging device such as imaging
device 1306 and/or a C-arm 1308 device. It may be desirable to take
x-rays of patient 210 from a number of different positions, without
the need for frequent manual repositioning of patient 210 which may
be required in an x-ray system. As illustrated in FIG. 12A, the
imaging system 1304 may be in the form of a C-arm 1308 that
includes an elongated C-shaped member terminating in opposing
distal ends 1312 of the "C" shape. C-shaped member 1130 may further
comprise an x-ray source 1314 and an image receptor 1316. The space
within C-arm 1308 of the arm may provide room for the physician to
attend to the patient substantially free of interference from x-ray
support structure 1318. As illustrated in FIG. 12B, the imaging
system may include imaging device 1306 having a gantry housing 1324
attached to a support structure imaging device support structure
1328, such as a wheeled mobile cart 1330 with wheels 1332, which
may enclose an image capturing portion, not illustrated. The image
capturing portion may include an x-ray source and/or emission
portion and an x-ray receiving and/or image receiving portion,
which may be disposed about one hundred and eighty degrees from
each other and mounted on a rotor (not illustrated) relative to a
track of the image capturing portion. The image capturing portion
may be operable to rotate three hundred and sixty degrees during
image acquisition. The image capturing portion may rotate around a
central point and/or axis, allowing image data of patient 210 to be
acquired from multiple directions or in multiple planes. Although
certain imaging systems 1304 are exemplified herein, it will be
appreciated that any suitable imaging system may be selected by one
of ordinary skill in the art.
[0076] FIGS. 13-17 illustrate exemplary images, systems, and/or
methods for measuring the depth of surgical instrumentation during
an operation on a patient. Implementations of the measurement
systems and methods described may be conducted by the robot systems
as previously described including robot systems 100, 300, and 600
and the components discussed thereto.
[0077] As an exemplary embodiment, a surgeon may position a long
shaft such as a dilator tube within a secondary tracked tube, such
as the robot's end effector guide tube or a free tracked external
guide tube, to a known depth. These components have also been
discussed as noted above. The depth may be the exact depth needed
such that the dilator tube contacts the target bone of the patient.
By referencing the secondary tracked tube, measuring the depth of
the dilator tube may be conducted without tracking the dilator tube
itself.
[0078] Depth measurements may be based on the tracked guide
tube--either the robot's end effector guide tube or other navigated
guide tube--being in a "tube-centric" view. As an example,
viewplanes of various CT scans of a patient's target bone may be
chosen such that the 3D-tracked position of the guide tube (for
example, positional tracking as earlier discussed) is aligned to be
simultaneously within two non-parallel planes, or in other words
coincident with the line formed by the intersection of two planes.
For example, in a posterior surgery where the guide tube is aligned
such that it is aimed down a pedicle of a vertebral body, two
substantially orthogonal anatomical viewplanes may be selected such
that one viewplane is predominantly sagittal, with the guide tube
aligned along the vertical axis of the 2D viewplane, while the
other viewplane is predominantly axial, with the guide tube also
aligned along that 2D viewplane's vertical axis. FIG. 13
illustrates an exemplary 2D image plane (slice) 1600 through a 3D
computed tomography (CT) image volume showing vertebrae of a
patient, including vertebral body 1602, a guide tube 1604, and
vector 1606 from a sagittal viewpoint of the patient. FIG. 14
illustrates an exemplary 2D image plane (slice) 1700 through a 3D
CT image volume showing vertebral body 1602, guide 1604, and vector
1606 from an axial view point of the patient.
[0079] Although FIGS. 13 and 14 show particular viewplanes, other
pairs of viewplanes could be selected such that the tracked guide
tube's central axis is coincident with the line found from the
intersection of the two planes. In addition, the 2D representation
on each plane of the tube does not need to be vertical or even in
the same direction in the two planes.
[0080] Vector 1606 may be depicted as extending from a
representation of guide tube 1604 and overlaid on the images 1600
and 1700. On vector 1606, measurements may be shown incrementally
with tick or hatch marks 1608. Marks 1608 may start from one end of
guide tube 1604 (such as the top of proximal end 1610 and
represented as position zero), with measurement increasing toward
and beyond a distal end of the guide tube 1612. Guide tube 1604 may
be coincident with the viewplanes because it is then known that any
anatomical point along vector 1606 is reachable by a tool inserted
through guide tube 1606. If guide tube 1604 was not coincident with
the viewplanes, a vector may still be drawn but the vector may a
projection on the 2D view that may not intersect the anatomy
visualized on the viewplane.
[0081] Marks 1608 on vector 1606 may be toggled on or off as
needed. Additionally, as a user independently zooms in or out on a
viewplane, the frequency and labeling of marks 1608 may be
automatically modified to minimize clutter while still providing
useful information to the user regarding the depth. For example, as
shown in images 1800, 1900, and 2000 of FIGS. 15, 16, and 17,
respectively, labels 1802 could be included at a rate of one label
every 20 mm and marks 1606 at a rate of one hatch mark every 10 mm
for a particular level of zoom (See FIG. 15). As zoom is increased
to 1.5 times the original zoom (compare FIG. 16 to FIG. 15), labels
1802 could automatically switch to a rate of one label every 10 mm
and marks 1606 could automatically switch to a rate of one hatch
mark every 5 mm. Then, as zoom is increased to 3.0 times the
original zoom (compare FIG. 17 to FIGS. 15 and 16), labels 1802
could automatically switch to a rate of one label every 5 mm and
the marks 1606 could automatically switch to a rate of one hatch
mark every 2.5 mm.
[0082] As an example, the decision for automatically switching rate
and frequency of marks 1606 and labels 1802 could be that between
two points A and B, marks 1606 may be present from the first to the
last visible point on a line crossing the viewplane along the guide
tube's central vector. Within points A and B, an optimal selection
would involve increments representing well rounded values, such as
tens, fives, ones, halves, and quarters. The frequency of labeling
may be a rate of one label every C marks. For example, these rules
would be able to dictate the behavior shown in FIGS. 15-17 if A=10,
B=15, C=2. With zooming, the surgeon could read with good precision
the distance from the top of the guide tube to the bone, for
example 149 mm in FIGS. 15-17.
[0083] Using this measurement technique, the inserted instrument or
dilator may have graduated markings and labels starting at zero at
the distal end of the instrument and increasing toward the proximal
end. FIG. 18 depicts an instrument 2100 with graduated markings
2102 showing this example. Markings 2102 may be present along the
entire length of instrument 2100. In many cases, it may be
unnecessary to include markings 2102 along the first length of
instrument 2100 until the length of guide tube 1604 has been
exceeded since markings 2102 would not be visible at the proximal
end of guide tube 1604 with instrument 2100 inserted into guide
tube 1604 and just beginning to protrude distally.
[0084] FIG. 19 illustrates instrument 2100, with markings 2102,
inserted into guide tube 1604. The surgeon would insert instrument
2100 with markings into the tracked guide tube 1604 and would read
the position of the inserted instrument 2100 from its graduations
or markings 2102. This reading may indicate whether instrument 2100
reached the desired depth. For example, when inserting a dilator,
if the length observed on markings 2102 agrees with a length
measured from the measurement representing the distance from the
proximal end of guide tube 1604 to the target bone of the patient,
the surgeon would know that instrument 2100 was touching the target
bone. If the length read from instrument 2100 was 3 mm less than
the length from the measurement between the guide tube to the
target bone, the surgeon would know that they must insert
instrument 2100 a distance of 3 more millimeters before bone would
be touched.
[0085] As described above, a distance from the top tip of
instrument 2100 to the proximal end (top) of the tracked guide tube
1604 is being read from instrument 2100 by the use of markings
2102. Under the same principles of the present disclosure,
measurement techniques may be configured such that the graphical
images of the patient anatomy show the distance from the distal end
(bottom) of tracked guide tube 1604, or the distance from a window
through the guide tube 1604 to the tip of the instrument 2100. The
insertion depth would then be read from these other locations,
i.e., from the bottom of the guide tube or observed through a
window in the guide tube, to draw the same information about the
depth of insertion of the instrument.
[0086] FIG. 20 illustrates a method 2200 for determining the
distance or depth in order to contact a target bone of patient
consistent with the principles of the present disclosure. At step
2202 a computer subsystem, such as those previously described,
receives a scan, for example a CT scan, that may represent the
target bone of a patient from different viewplanes or viewpoints.
The computer subsystem may receive a scan of a first viewplane and
a second viewplane that form an intersection of views of the target
bone in an image space. At step 2204, the computer subsystem may
receive information indicative of a position of a guide tube of the
surgical robot system in navigational space. At step 2206 the
computer of the computer subsystem may determine a distance between
a distal portion of the guide tube to the target bone of the
patient. The distance may be determined such that a central axis of
the guide tube is coincident to the line of intersection formed
between the first viewplane and the second viewplane. At step 2608
the computer subsystem may display a vector indicative of the
distance to contact the target bone of the patient on at least one
of the first viewplane scan and the second viewplane scan. The
vector may include any or all of the attributes a previously
describe and those skilled in the art would recognize that the
visual depiction of the vector may be represented in other way to
indicate distance measurements that would fall within the scope of
the present disclosure.
[0087] While the invention has been disclosed in connection with
the preferred embodiments shown and described in detail, various
modifications and improvements thereon will become readily apparent
to those skilled in the art. Accordingly, the spirit and scope of
the present invention is not to be limited by the foregoing
examples, but is to be understood in the broadest sense allowable
by law.
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